Mobile machines, including bulldozers, wheel loaders, motor graders, and other types of heavy equipment, can be used for a variety of tasks. In order to accomplish these tasks, the machines typically include a primary mover such as an internal combustion engine that is coupled to traction devices of the machine to propel the machine. The primary mover can also be coupled to power one or more work implements attached to the machine.
One type of mobile machine is known as a “high-idle” machine. During operation of a high-idle machine, a speed of the primary mover is generally set to a level that is sufficient to quickly produce a maximum power output that could be required by the traction devices and the work implement. That is, in order to help ensure that the machine has power sufficient to move the machine and work tool under all conditions, the primary mover is set to a predetermined high speed, even if the current task being accomplished by the machine currently demands less power from the primary mover. Although very responsive to changing demands, this high level output may be inefficient in some situations and could result in high fuel consumption, excessive exhaust emissions, elevated temperatures, and high levels of engine noise.
One way to reduce the fuel consumption, exhaust emissions, temperatures, and noise associated with a high-idle machine is disclosed in WO Patent Publication No. 2009/082446 (the '446 publication) of Roth et al. published on Jul. 2, 2009. The '446 publication discloses a high-idle machine having a control system that monitors a travel direction of the machine and selectively adjusts an engine speed of the machine based on the travel direction. In particular, when the control system detects a reverse driving direction of the machine, the control system reduces an engine speed of the machine away from a high-idle speed. When driving in the reverse direction, machine work tools are inactive or have reduced engagement with the earth, thus requiring reduced power from the engine. Accordingly, engine speed can be reduced during reverse travel to improve fuel consumption, emissions, and noise, without significantly affecting a responsiveness of the machine in a negative way.
The disclosed control system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.